Limitations of reproduction medicine in male subfertility. Treatment of severe spermatogenesis disorders

Treatment of severe male subfertility has become available since the intrac ytoplasmic injection of a single sperm into an oocyte was successfully appl ied for the first time in 1992. Moreover, also with the use of testicular s permatozoa for this procedure fertilization and pregnancies could be accomp lished. This review addresses the development of these techniques and discu sses achievements and problems as well as future aspects of the feasability of early spermatid injection are stressed. Futhermore it includes the basi c elements of spermatogenesis and the major concerns regarding the underlyi ng genetic reasons for spermatogenic failure.